- Modern ceiling lights rely on electricity from either a local generator or a commercial power grid. When electricity enters the home, it first enters a circuit breaker or, in older homes, a fuse box. If the electrical circuit powering the ceiling lights becomes overloaded or fails to operate properly, a circuit breaker detects the fault and interrupts the circuit, turning off the ceiling lights and preventing potential fires. Before the electricity flows to the ceiling light, though, it first must pass through a light switch.
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If ceiling lights received a constant flow of electricity, the lights would always remain "on" and bulbs would frequently burn out. That's why switches are installed to interrupt the flow of electricity to the ceiling lights and allow users to turn the lights off when not in use. Although a variety of switches exists, Don Vandervort's Home Tips website indicates that the light switch most familiar to most users is a simple "On/Off" device known as a "Single pole switch." In the off position, those switches maintain a short distance between two portions of the electrical circuit; the gap in the circuit prevents electricity from passing. When a user flips the switch to the on position, a metal component slides to connect the two portions of the circuit, allowing electricity to flow to the ceiling lights.
A number of other switch types--including dimmer switches, motion sensing switches and even computer-controlled switches---offer an array of options for activating and deactivating lights. Despite the advanced functions of those switches, all switches activate ceiling lights by completing or interrupting the electrical circuit on which the overhead light bulb resides. -
As the electricity moves through a light bulb, a small portion of wire inside the bulb resists the electrical flow. As that small wire, known as a filament, resists the flow of electricity, it becomes glowing hot, and it gives off light. In some cases, usually in commercial installations, the flowing electricity interacts with special chemicals inside a coated glass tube. As the electricity flows through the chemicals, they begin to glow (or fluoresce) to create fluorescent ceiling lights.
Although both filament light bulbs, known as incandescent lighting, and fluorescent lighting both rely on electrical current, the high resistance in an incandescent bulb burns through electricity more quickly, creating a condition of high electrical use and, for many home users, higher power bills.
